This invention relates to gear shifting mechanisms of the type in which gear ratio changes are brought about by back and forth movement of the gear shift lever. A gear shift mechanism of this general class is disclosed in U.S. Pat. No. 3,636,739. The instant invention is directed to the achievement of a shifting mechanism having capabilities which permit its use with five-speed transmissions and to other improvements. The embodiment of the invention disclosed herein is particularly intended for use on competitive type vehicles used for high acceleration racing events or drag races. The principles of the invention can be used also on vehicles intended for over the road service.
Drag racing has for its object the achievement of an extremely high speed in a very short distance by the vehicle. For example, it is common for a drag racing vehicle to achieve a speed of 140 or more miles per hour in less than 10 seconds on a course of one-fourth mile. Racing vehicles are equiped with manual transmissions having four speed or five speeds and the driver must, therefore, change gears 3 or 4 times during the extremely short time period of the race. Obviously, then it is critical that the gears be changed almost instantaneously. The back and forth gear changing mechanism of the above-identified U.S. patent is highly regarded for the reason that gears are changed by a simple straight motion of the gear shift lever rather than a motion which follows an H pattern, however, as noted above, this mechanism is intended for use in a four speed transmission.
Many of the transmissions used in racing events have five forward speeds and the need for a straight action five speed changing mechanism has been recognized for some time. The instant invention has this capability as well as a degree of versatility which permits its use with a four speed transmission.
It is accordingly an object of the invention to provide an improved gear changing mechanism for a manual automotive transmission. A further object is to provide a mechanism for use in competitive acceleration racing. A further object is to provide a durable and rugged speed changing mechanism which will withstand the conditions of competition acceleration racing events. A further object is to provide a straight action gear changing mechanism which can be used with a four speed transmission and with a five speed transmission.